The process of iontophoresis was described by LeDuc in 1908 and has since found commercial use in the delivery of ionically charged therapeutic agent molecules such as pilocarpine, lidocaine and dexamethasone. In this delivery method, ions bearing a positive charge are driven across the skin at the site of an electrolytic electrical system anode while ions bearing a negative charge are driven across the skin at the site of an electrolytic system cathode.
Earlier, and some present, iontophoretic devices have been typically constructed of two electrodes attached by adhesive materials to a patient, each connected by a wire to a remote power supply, generally a microprocessor-controlled electrical instrument.
A recent publication has indicated that Sumatriptan can be transdermally transported effectively using iontophoresis (Femenia-Font et al, J. Pharm Sci 94, 2183-2186, 2005). In this study, iontophoretic transport of Sumatriptan was found to be at a rate 385 fold higher than passive transport.
Another recent study has concluded that iontophoresis can be useful in the delivery of anti-migraine compounds. In this study, a two-component system comprised of an electronic controller connected by wire to a transdermal patch was used to deliver Zolmatriptan. The company presenting the results from this study has concluded that programmable capability of its iontophoresis units may allow rapid initial delivery for fast action, while a sustained, low level maintenance dose can be utilized for a prevention of headache recurrence. A significant limitation of this device lies in the two-component structure of the delivery system; the wire connections between the controller and patches are a nuisance to the wearer. Additionally, programmable controllers can be expensive if utilized on a single use basis, or lost, contaminated, broken, etc. if used on a reusable basis.